Firearm cartridge

ABSTRACT

A firearm cartridge having a propulsion charge for a bullet and a sealing element at the rear thereof composed of a combustible material which burns more slowly than the propulsion charge so as to maintain its sealing effect while the propulsion charge is exploded and thus prevent flashback but will subsequently completely burn out to leave the cartridge chamber of the firearm clear for reloading.

United States Patent 1151 3,682,097 Rausing 1451 Aug. 8, 1972 [54]FIREARM CARTRIDGE 2,632,391 3/1953 Kintzinger 102/38 [72 lnvemor: GadAnders musing, Land, Sweden 3,345,945 10/1967 Quinlan et a1. ..102/383,396,658 8/1968 Scanlon, Jr. et a1. 102/38 [731 Asslgnw Enterpriseslimited, Hamfl- 2,299,465 10/1942 Coffman 102/1910. 1

ton, Bermuda 1 [22] Filed: Sept. 8, 1969 FOREIGN PATENTS OR APPLICATIONS455,382 1/1928 Germany ..l02/D1G. l App! 855336 7,193 1891 Great Britain..102/43 P 519,341 3/1940 Great Britain ..102/D1G. 1 [30] ForeignApplication Priority Data 0C1. 14, [968 Sweden ..13799 Prim? W SlabAttorney-fierce, Scheffler & Parker [52] US. Cl ..l02/38, l02/D1G. l,102/40,

102 44 [57] ABSTRACT 51 1m. (:1 ..F42b 9/16 A firearm camid h 1 h f geavlng a propu SlOn c arge or a [58] Field of Search ..102/38, DIG. 1,44, 45, 86.5, bullet and a sealing element at the rear thereof 102/40posed of a combustible material which burns more slowly than thepropulsion charge so as to maintain its [56] References Cited sealingeffect while the propulsion charge is exploded UNITED STATES PATENTS andthus prevent flashback but will subsequently 1 t 1 b t t 1 th art 'd h hf 487,125 ll/l892 DeLatouche........l02/D1G. 1 3,353, ?,,fi gee am em1,353,118 9/1920 Thompson ..102/41 1,808,877 6/1931 Young ..102/40 6Chins, 1 Drawing figure FIREARM CARTRIDGE This invention relates to afirearm cartridge, comprising bullet and propulsion charge.

It has been known for a long time how to combine the bullet andpropulsion charge in a self-exploding cartridge which usually alsoincludes a primer. In known cartridges, the propulsion charge is usuallycontained in a cartridge case of metal, cardboard, plastic or some othersimilar material. There are usually one or more projectiles pressed intoone end wall whose center portion is usually fitted with a primer,through the agency of which the propulsion charge can be ignited. Thesaid end wall, which is usually made of metal, also has an importantduty as a gastight seal between the breech and the bolt, in order toprevent flashback when the bullet is fired. It is quite natural thatthis duty to act as a seal is very important, since the flashback whichmay arise if there were no seal may easily injure the person firing theweapon and/or affect the working and life of the mechanism.

The self-exploding cartridges available are certainly very efficientfrom the point of view of forming a gastight seal and are convenient tohandle, but they have the drawback that they are comparatively expensiveand that the case which remains in the chamber after firing must beremoved before a new cartridge can be inserted. A very high proportionof the cost of the cartridge is due to the cost of the case. If the casecan be eliminated, the cartridge can be made considerably cheaper andnaturally also lighter, and the absence of the case means that themechanism of automatic weapons can be made simpler and lighter, sincethere is no need for an extractor to withdraw the case from the chamberafter the bullet has been fired. The cartridge can also be made shorterwhich in turn makes possible a shorter and lighter mechanism and ahigher firing rate.

There is no difficulty involved in moulding a body of powder or someother explosive material into a certain shape defined by the shape ofthe chamber of the weapon and thereby also partly embedding a bullet inthe moulded body, and the techniques for such operations have alreadybeen evolved. Solution of the sealing action is a greater problem, andit seems inescapable that the cartridge must be provided with some kindof sealing washer or sealing flange in order to prevent the occurrenceof flashback.

This invention provides a solution to this problem, without howeverrelinquishing for this reason the requirement that there shall be noneed for portions of the cartridge to be removed from the chamber afterfiring. The invention is thereby characterized by the fact that thepropulsion charge consists of a moulded, preferably cylindrical, body ofan explosive material, for instance powder, into which body there isaffixed a bullet, and by the fact that the said preferably cylindricalbody exhibits a ringshaped or washer-shaped sealing device whichsurrounds the end of the propulsion charge, which device entirelyconsists of a combustible material. One constructional version of theinvention will be described below by reference to the attacheddiagrammatic drawing which shows a cartridge in accordance with theinvention.

The cartridge shown in the FIGURE consists of a propulsion charge 1 madeup of a moulded body of powder. The bullet is denoted 2 and the rearanchorage of the bullet by 5. The sealing device is denoted 3 and theprimer 4.

The powder material is moulded in a mould that has been made to fit theshape of the chamber of the weapon in which the cartridge is to be used.In conjunction with the moulding operation, the propulsion charge 1 isin a suitable manner joined onto the bullet 2 which may at its rear endhave a dovetail anchorage, by means of which the bullet 2 can beembedded in the propulsion charge 1. The propulsion charge 1 is alsoformed at its rear end in such a way that the sealing device 3, producedin a separate operation, can be fitted into the propulsion charge. Thesealing device 3 consists in the version shown of a washer-shaped endportion with a flange 6 and a central hole. The sealing device 3 may forinstance be made of nitrocellulose or some other easily combustiblematerial which is yet comparatively stable mechanically. The primer 4situated at the central part of the sealing device 3 consists of aprimer containing a charge that is ignited by a firing pin being thrownagainst the wall of the primer 4. [n a conventional primer, both theanvil and the case are made of metal. In primers for cartridges of thetype in accordance with the invention, they are made from an entirelycombustible material with a combustion time the same as, or shorterthan, that of the charge material. The seal and the primer can be madein one piece. lgnition can also take place in some other way, e.g., bymeans of compressed air or an electrical primer which directly actuatesthe propulsion charge.

When the cartridge in accordance with the drawing is to be fired, it isfirst placed in the chamber, which has been adapted to fit thecartridge, of a weapon. In the example shown, the cartridge andnaturally the chamber of the weapon also are slightly conical, but it isnaturally also possible to have a cylindrical chamber.

After the cartridge has been inserted into the chamber and this has beenlocked, the propulsion charge 1 is ignited and undergoes rapidcombustion, whereupon a high pressure develops in the chamber. This highpressure has the effect that the sealing device 3 is forced backwardsagainst the rear wall of the chamber and that the bullet 2 is ejectedthrough the barrel of the weapon. The propulsion charge 1 is naturallynot consumed instantaneously, and generally speaking combustion of thepropulsion charge proceeds the whole time that the bullet 2 is insidethe barrel, and owing to the increasing pressure, the bullet isaccelerated so as to reach its maximum velocity at the muzzle. After thebullet has left the barrel, the pressure in the barrel and chamber willnaturally drop. During the time that the high pressure in the chamber isacting, there are high stresses set up on the sealing device 3, whichfact prevents hot gases, the flashback, being ejected through the rearwall of the chamber. Since the sealing device 3 is made from acombustible material, combustion of the sealing device commencessimultaneously with ignition of the propulsion charge 1. The combustiontimes of the propulsion charge 1 and the sealing device 3 respectivelyare however adjusted in such a way that the sealing action of thesealing device is maintained during the whole of the combustion time ofthe propulsion charge 1, which time is however very short. This meansthat the dimensions of the sealing device 3, i.e., preferably itsthickness, must be adapted to the combustion velocity of the material insuch a way that complete combustion of the sealing device 3 does nottake place before the propulsion charge 1 has completely burned away orthe bullet has left the barrel.

it is important that complete combustion of both the propulsion chargeand the sealing device takes place so that such solid combustionproducts as may hinder insertion into the chamber of a new cartridge arenot left behind.

It is possible to produce sealing devices of the above type which arecompletely burned 0.001 0.5 second after the bullet has been fired,whereby the sealing device, despite the short combustion time, will havebeen able to exercise the required sealing action so that there is noflashback when the bullet is tired.

It is thus possible, using cartridges in accordance with the invention,to achieve a very high firing rate in automatic weapons, and at the sametime ammunition costs will be considerably lower and there will be norefuse" in the shape of empty cartridge cases.

] claim:

l. A firearm cartridge comprising a propulsion charge of explosivematerial molded in the form of a body having a substantially circularcross section, a bullet element affixed to the forward end of said bodyfor propulsion thereby, a washer-like sealing means at the opposite endof said body, said washer-like sealing means being composed of acombustible material having a burning rate slower than the burning rateof said propulsion charge to provide a sealing action during the entireburning of said propulsion charge and thus prevent flashback and beconsumed by its own combustion, and primer means for igniting thepropulsion charge.

2. A cartridge as claimed in claim 1 wherein said propulsion charge hasan annular recess thereabout and the washer-like sealing means comprisesa rear end wall and an annular flange thereabout forming a coex' tensivesurface with said propulsion charge, said flange being seated in saidannular recess of the propulsion charge.

3. A cartridge as claimed in claim 1 wherein said primer means comprisesa primer cap disposed centrally of said washer-like sealing means.

4. A cartridge as claimed in claim 1 wherein the washer-like sealingmeans is composed of a combustible material which will be completelyburned away in 0.001 to 0.5 seconds after ignition of said propulsioncharge.

5. A cartridge as claimed in claim 1 wherein the propulsion charge iscomposed of a powder charge and the washer-like sealing means iscomposed of nitrocellulose.

6. A cartridge as claimed in claim 1 wherein the primer means and thewasher-like sealing means are made in one piece.

III 0 l

1. A firearm cartridge comprising a propulsion charge of explosivematerial molded in the form of a body having a substantially circularcross section, a bullet element affixed to the forward end of said bodyfor propulsion thereby, a washerlike sealing means at the opposite endof said body, said washerlike sealing means being composed of acombustible material having a burning rate slower than the burning rateof said propulsion charge to provide a sealing action during the entireburning of said propulsion charge and thus prevent flashback and beconsumed by its own combustion, and primer means for igniting thepropulsion charge.
 2. A cartridge as claimed in claim 1 wherein saidpropulsion charge has an annular recess thereabout and the washer-likesealing means comprises a rear end wall and an annular flange thereaboutforming a coextensive surface with said propulsion charge, said flangebeing seated in said annular recess of the propulsion charge.
 3. Acartridge as claimed in claim 1 wherein said primer means comprises aprimer cap disposed centrally of said washer-like sealing means.
 4. Acartridge as claimed in claim 1 wherein the washer-like sealing means iscomposed of a combustible material which will be completely burned awayin 0.001 to 0.5 seconds after ignition of said propulsion charge.
 5. Acartridge as claimed in claim 1 wherein the propulsion charge iscomposed of a powder charge and the washer-like sealing means iscomposed of nitrocellulose.
 6. A cartridge as claimed in claim 1 whereinthe primer means and the washer-like sealing means are made in onepiece.